Hitherto, a considerable reduction in time for photographic processing of radiographic sensitive materials for medical use and X-ray sensitive materials for industrial use has been achieved by unceasing improvements in sensitive materials and processing agents. In particular, the reduction in processing time is very important for radiographic sensitive materials for medical use, because in an emergency a doctor should not lose any time, even 1 second, in making a diagnosis and giving a treatment. In the case of industrial X-ray sensitive materials, on the other hand, it is necessary to coat a large quantity of silver since the sensitivity of sensitive materials of this kind to X-rays largely depends on the silver coverage thereof, and consequently a much longer processing time is required of the industrial X-ray sensitive materials in contrast to radiographic sensitive materials for medical use. For the present, a rapid processing with an automatic developing machine is popular, and the Dry to Dry total photographic processing time ranges from 90 sec. to 3.5 min. for radiographic sensitive materials for medical use, while it ranges from 5 min. to 11 min. for industrial X-ray sensitive materials. Under these circumstances, a further reduction in such a Dry to Dry processing time is desired.
In order to reduce the photographic processing time, the processing time in each step, including development, fixing, washing and drying should be shortened. A reduction in development time is generally known to be achieved by enhancing the activity of the developer through increasing the concentration of the developing agent, pH, development temperature or so on, or by increasing the development promotability of a silver halide emulsion itself. However, enhancement of the activity of a developer is not necessarily bound up with enhancement of the value as a commodity since it brings the cost up and/or spoils the keeping stability of the developer itself. On the other hand, washing and drying times largely depend upon the thickness and the swelling degree of the coated layers that constitute a sensitive material. Therefore, it is possible to reduce such processing times by previously using a hardener in a sufficient quantity to heighten the cross-linking degree of gelatin. However, the heightening of the cross-linking degree of gelatin causes a drop in covering power which necessitates an increase in silver coverage, and is also bound up with lowering of sensitivity and development promotability, and further a decrease in fixing speed. As described above although there are methods for reducing the processing time in each step, such methods are attended by ill effects, and it is difficult to ensure a reduction beyond the present situation in regard to the Dry to Dry processing time.